Ethereum: How to generate keypair completely offline?
Generating a Fully Offline Key Pair in Ethereum: A Step-by-Step Guide
In recent years, concerns about data security and anonymity online have increased interest in offline cryptography. One such method is to generate a fully offline key pair using dice, calculators, paper, and a pen. This article will explore the procedure and formulas used to generate an Ethereum offline key pair.
What is an offline key pair?
An offline key pair consists of two private keys: one for public use (or signing) and one for secure storage (or personal use). In this context, generating a fully offline key pair means creating both public and private keys that can be used without being transmitted over the internet.
Generating an Ethereum Key Pair Offline
To create an offline Ethereum key pair using dice, calculator, paper, and pen, follow these steps:
Step 1: Choose a Seed Phrase or Masterseed
A seed phrase is a string of words that contains the private keys of your Ethereum wallet. To create an offline key pair, you will need to generate a master seed phrase (or master phrase) from this seed phrase.
You can use any method to derive a seed phrase from another private key, such as:
- Using paper and pen
- Using a random number generator (RNG)
- Using a cryptographically secure pseudo-random number generator (CSPRNG)
For this example, we will assume that you have a pre-generated masterseed.
Step 2: Create an offline Ethereum address
To create an offline Ethereum address, you can use the following formula:
offlineAddress = "0x" + masterseed.slice(0, 4) + "..."
Replace "..." with the actual seed phrase in base64 encoded format (e.g. "aV1c2Vy").
For example:
offlineAddress = "0x9e6bf3b7..."
Step 3: Get the private key from the offline address
To get the private key, use a cryptographic hash function such as SHA-256 or BLAKE2. Here is an example of using SHA-256:
privateKey = offlineAddress.split(“0x”)[1].replace(“+”, “”)
privateKey = offlineAddress.split("0x")[1].replace("+", "")Step 4: Get the private key from the offline address and seed phrase
To get the private key from the offline address, seed phrase, and public key (not shown here), you can use a cryptographic hash function such as SHA-256 or BLAKE2.
Step 5: Get the private key from the offline address and seed phrase (continued)
To get the private key from the offline address, seed phrase, public key, and another hash function such as SHA-256 or BLAKE2, use the following formula:
privateKey = offlineAddress.split(“0x”)[1].replace(“+”, “”)
python
def derive_private_key(offline_address, seed_phrase):
masterseed = seed_phrase.replace(" ", "")
private_key_derived_from_masterseed = offline_address[:4] + masterseed[:5]
private_key_derived_from_seedphrase = offline_address[6:]
Remove prefix "0x"
return derive_private_key_from_hash(private_key_derived_from_masterseed, private_key_derived_from_seedphrase)
def derive_private_key_from_hash(hash_value, seed_phrase):
hash_value_base64 = base64.b64encode(hash_value).decode('utf-8')
masterseed = hash_value_base64[:4]
return offline_address[:4] + masterseed[:5]
offline_address = "0x9e6bf3b7..."
private_key = derive_private_key(offline_address, offline_address)
print(private_key)
Output: your private key in hexadecimal format
“
Conclusion
Generate an offline Ethereum key pair using dice, calculators, paper, and pen are a feasible way to achieve complete anonymity offline. By following the steps above, you can create a secure offline Ethereum wallet that can be used without transmitting sensitive information over the internet.